Monolithic Power Systems Inc. MP2358DQ-LF-P

Overview

MP2358DQ-LF-P from Monolithic Power Systems is a 2A, 23V-input synchronous step-down DC/DC converter in QFN10 (3mm × 3mm) package with integrated 0.18Ω high-side MOSFET, fixed 370kHz switching frequency, 0.92V to 16V adjustable output, and current-mode control for fast transient response in power supply rails for embedded systems.

For engineers reviewing the MP2358DQ-LF-P datasheet, MP2358DQ-LF-P pinout, MP2358DQ-LF-P application, or MP2358DQ-LF-P equivalent, this device is selected for compact, high-efficiency point-of-load conversion where input range (4.75–23V), thermal robustness (–40°C to +85°C), and programmable soft-start are critical design requirements.

Technical Context

The MP2358DQ-LF-P implements peak current-mode control with internal slope compensation, enabling stable operation across wide duty cycles and supporting up to 90% maximum duty cycle. Its transconductance error amplifier (GEA = 550–1150 μA/V) and COMP pin interface allow precise loop compensation using external R-C networks.

It integrates dual MOSFETs - a 0.18Ω high-side switch and 10Ω low-side switch - and features cycle-by-cycle overcurrent protection, thermal shutdown at 160°C, and UVLO with 210mV hysteresis. The bootstrap circuit (BS pin) supports high-side gate drive via external capacitor, enabling efficient operation even at high VIN/VOUT ratios.

Key Specifications

Pinout & Package

MP2358DQ-LF-P uses a thermally enhanced QFN10 (3mm × 3mm) package with exposed thermal pad on underside. Pin 1 is marked by top-side dot; pins are numbered counterclockwise. The exposed pad must be soldered to PCB ground plane for optimal thermal performance and electrical stability.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down converter applications.

Compared with MP2358DQ-LF-P, MP2357DQ-LF-P offers identical feature set at reduced current capacity, while RT7272BGJ6F trades pin compatibility and analog control flexibility for higher frequency and integrated bootstrap - making MP2358DQ-LF-P optimal for designs needing proven thermal performance, layout simplicity, and configurable startup behavior.

Availability

MP2358DQ-LF-P is available at Aetrix Electronics and suitable for industrial IoT sensor nodes, automotive body control modules, and portable medical diagnostic devices requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP2358DQ-LF-P includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance analog and power ICs, with core expertise in DC/DC conversion, motor drivers, and LED lighting controllers.

The MP2358 belongs to MPS's mainstream synchronous buck converter product line, designed specifically for space-constrained, high-efficiency point-of-load applications in industrial, automotive, and consumer electronics where input voltage range and thermal resilience are critical.

FAQ

What is the minimum recommended input voltage for reliable startup?

The MP2358DQ-LF-P requires ≥4.75V at the IN pin to initiate regulation. Below this, the internal UVLO prevents switching; the EN pin threshold (2.50V typical) must also be met if externally controlled. Startup is guaranteed across –40°C to +85°C ambient when input meets spec.

Can the MP2358DQ-LF-P operate without an external bootstrap capacitor?

No - the BS pin requires an external capacitor (typically 10nF to 100nF ceramic) connected between BS and SW to provide gate drive voltage for the internal high-side MOSFET. Omitting it prevents high-side conduction and causes complete failure to regulate.

How does the current limit behave above 40% duty cycle?

Above 40% duty cycle, internal slope compensation modifies the current limit threshold to prevent subharmonic oscillation. Per datasheet Note 4, the effective current limit rises from 3.4A (typical) to maintain stability - verified in electrical characteristics tables under "Current Limit (4)".

Is the exposed thermal pad electrically connected internally?

Yes - the exposed pad is internally tied to GND. It must be soldered to a PCB copper pour connected to the main GND plane to ensure both thermal dissipation (θJC = 12°C/W) and low-noise signal reference integrity.

What output capacitor ESR range is supported for stable operation?

The MP2358DQ-LF-P is optimized for ceramic capacitors (ESR < 10mΩ), but supports tantalum and low-ESR electrolytics (up to ~100mΩ). Stability is maintained across ESR values due to current-mode control and COMP-pin compensation flexibility - confirmed in Application Information section.

Does the SS pin require a minimum capacitor value for safe startup?

No minimum is specified, but 1nF–100nF is typical. Smaller values (e.g., 1nF) yield faster ramp times (~1ms); larger values (e.g., 100nF) extend ramp to ~100ms. Open-circuit SS enables immediate startup - verified in PIN FUNCTIONS table and TYPICAL APPLICATION schematic.

What is the maximum achievable output voltage with standard feedback resistors?

With R2 = 10kΩ (typical), the output can be set up to 16V per datasheet specification. Higher outputs require scaling R1 accordingly using V_OUT = 0.92V × (1 + R1/R2); however, absolute maximum V_IN remains 23V, limiting practical V_OUT based on duty cycle constraints.